Treatment of textiles

ABSTRACT

THERE IS PROVIDED AN IMPROVEMENT IN THE PROCESS WHEREBY TEXTILE MATERIALS ARE SOLVENT SCOURED. THE SOLVENT IS FLASHED OFF AND THEREAFTER THE TEXTILE MATERIAL IS FINISHED OR DYED. THE IMPROVEMENT RESIDES IN APPLYING THE FINISH OF DYESTUFF IN THE FLASH-OFF STAGE OF THE KNOWN PROCESS.

United States Patent 3,575,686 TREATMENT OF TEXTILES John William Case,Norman Frederick Crowder, and

Wilfred Arthur Stephen White, Runcorn, England, assignors to ImperialChemical Industries Limited, London, England No Drawing.Continuation-impart of application Ser. No. 549,498, May 12, 1966. Thisapplication Oct. 14, 1966, Ser. No. 586,663 Claims priority, applicationGreat Britain, June 24, 1965, 21,905/65 Int. Cl. D061 N02 US. Cl. 8-1426 Claims ABSTRACT OF THE DISCLOSURE There is provided an improvement inthe process whereby textile materials are solvent scoured. The solventis flashed off and thereafter the textile material is finished or dyed.The improvement resides in applying the finish or dyestuff in theflash-off stage of the known process.

This application is a continuation-in-part of copending application Ser.No. 549,498, filed on May 12, 1966, now US. Pat. No. 3,476,504.

This invention relates to a process for the treatment of textilematerials and more particularly to process improvements or modificationswhich can be used in conjunction with the scouring of textile materialswith organic solvents.

It is known, for example in UK. specifications Nos. 812,984 and 916,338to treat textile materials with an organic solvent, particularly achlorinated hydrocarbon solvent, in order to clean them. This procedureis sometimes termed a solvent scouring treatment. In such a process thetextile material is passed through a bath of organic solvent, underconditions which enable contamination to be removed from the textilematerials, and then the treated textile material laden with solvents ispassed through an apparatus in which the solvent is evaporated andrecovered. This final stage commonly termed the flash-oft stage, may becarried out using hot water or steam.

We have now found that this procedure is especially useful when carriedout in conjunction with dyeing the material while it is in an open andabsorbent condition by including a dyestuff in the water used in theflash-01f system. This procedure can be modified so as to apply afinishing agent to the material.

According to our invention we provide a process for the treatment of atextile material which comprises scouring the textile material with anorganic solvent, removing the solvent from the textile material in anaqueous flash-off stage and application of a dyestuif or finishing agentto the textile material in the aqueous flash-off stage.

When steam is used it is usual to pass the textile material from thesolvent bath through squeeze rollers to remove excess solvent, and thenthrough an aqueous flash-off stage which comprises a space in which thetextile material is contacted with steam and a water seal through whichthe textile material leaves the apparatus. In such a case the dyestufior finishing agent will be incorporated in the water seal.

When hot water and not steam is used in the flash-oft stage it is usualfor the textile material to pass from the solvent bath through squeezerollers to remove excess solvent and then directly into a bath of waterheld at a sufiiciently high temperature to flash-0E the solvent. In

such a case the hot water flash-off" bath will contain the dyestutf orfinishing agent.

Our process is particularly convenient when the textile material to beterated contains only solvent-soluble textile assistants, for exampleassistants (such as sizes), which have been applied to the textilefibres from solution in an organic solvent as is more fully described inour copending U.K. application No. 21,906/ 65.

By using, prior to the solvent scouring stage, textile assistants whichare entirely soluble in the organic solvent we find that the solventscouring stage can remove practically all contamination from the textilematerial and leave it in such a condition that, after the adherentorganic solvent is removed, it is thoroughly clean and absorbent and inan excellent condition for dyeing.

When the textile assistants used in the weaving of the textile materialare not entirely solvent-soluble, there may be a tendency for anyresidues remaining on the cloth after the solvent scouring stage tointerfere slightly with the efliciency of the stage in which the dye orfinishing agent is applied, though in many cases this may not be of moreimportance than slightly decreasing the efiiciency of finishing agent ordyestutf usage. It is however generally desirable to remove as muchcontamination as possible before the textile is passed to the stage atwhich the dye or finishing agent is applied, and if necessary an aqueousdesizing step may precede the solvent scouring step. A preliminaryaqueous desizing step is particularly advantageous when a starch,cellulose ether or similar size has been used on a fibre, for example oncellulose fibre such as cotton or rayon.

The solvents and techniques which can be used for the solvent scouringstage may be in particular any of those described more fully in UK.specifications Nos. 812,984; 916,338; 747,481; 749,705; 812,893;844,943; 825,402; 1,042,398 and patent application No. 9,975/65. Thusthe solvent may be in particular trichloroethylene, perchloroethylene,1,1,2-trichloro-1,2,2-trifiuoroethane or mixtures thereof. The choice ofsolvent to be used depends very much upon the particular textilematerial concerned and the solvent is best chosen so that its solventproperties and boiling point are such that its use will not adverselyaffect the textile material. In particular, it may be appropriate to usea low-boiling solvent, for example, 1,1,2-trichloro-1,2,2-trifluoroethane, in the case of textile materials whichare particularly sensitive to heat or solvent action.

During the solvent flash-off solvent or an azeotrope of the solvent andwater is vogorously evaporated thus leaving the textile material in anopen and highly absorbent state and we believe that one of theadvantages of our process lies in the application of the dyestulf orfinishing agent to the material while it is in such a highly absorbentstate, thus giving a high rate of uptake and a high and even penetrationof dyestutf or finishing agent.

The application of a dyestuli may involve the use of any of theconventional dyestuffs, dyeing assistants and auxiliary products knownin the art, and these may be selected appropriately to the textilematerial concerned. Suitable dyestuffs include water-soluble,water-dispersible and reactive dyes and suitable finishing agentsinclude brightening and softening agents and fiuoroescent whiteners. Thetemperature of the dye bath, when the textile material is dyed in ahot-water flash 01f, should be sufficiently high to ensure the rapidremoval of the solvent (a minimum temperature of 86 C. and 73 C. isrequired for perchloroethylene and trichloroethylene respectively). Whenthe textile is dyed in a Water seal after contact with steam thetemperature of the dye bath need not necessarily be so high. Times ofresidence in the solventscouring bath, the steam treatment chamberand/or the bath in which the dye or finishing agent are applied willvary with the textile material to be treated, the solvent used and thetype of dye or finishing agent to be applied. Suitable times may befound very easily by simple experiment, but in general we have foundthat times of from 10 to 60 seconds in the solvent bath, and from 10 to30 seconds in a steam flash-off chamber (if used) are suitable. The timeof residence in the bath in which the dyestuff or finishing agent isapplied to the textile material will vary with the method ofapplication, for example times of from 2 to 60 seconds are suitable fordyestuffs or finishing agents which are simply applied to the textilematerial in the bath and are then set on the material at a later stage,but times of up about minutes may be necessary if transfer of dyestuffor finishing agent onto the material occurs only in the bath and thereis no subsequent setting stage. The concentration of dyestuff orfinishing agent and the general conditions under which it is appliedwill be those well known in the art or will be slightly modified inobvious ways to suit the particular conditions pertaining.

The invention is illustrated but in no way limited by reference to thefollowing examples in which the parts are by weight.

EXAMPLE 1 100 parts of (a) a plain weave cotton fabric or (b) a heavycotton canvas or (c) a medium spun viscose rayon were separatelyimmersed in 5000 parts of boiling trichloroethylene for a period ofseconds. The fabric was removed from the trichloroethylene, squeezedbetween rollers to a total weight of 250 parts and entered directly into5000 parts of a boiling, aqueous dyebath containing 50 parts of thosedyes recorded in the Colour Index as (a) Direct Red 1 (CI 22310) (b)Direct Blue 86 (CT 74180 (0) Direct Blue 76 (CI 22410). After 30 secondsimmersion the fabric was removed, squeezed through rollers to a totalweight of 200 parts and dried in hot air. The fabric was in each of thenine possible combinations of the three individual fabrics with thethree individual dyestuffs dyed to a level, well penetrated shade.

EXAMPLE 2 100 parts of (a) Botany wool serge fabric (b) wool feltfabric, (c) spun nylon 66 fabric, ((1) a fabric woven from nylon 6filament were separately immersed in 5000 parts of boilingtrichloroethylene for a period of 30 seconds.

The fabric was removed from the trichloroethylene, squeezed betweenrollers to a total weight of 240 parts and entered directly into 5000parts of a boiling, aqueous dyebath containing parts of a dye recordedin the Colour Index as Acid Blue 138 (CI 62075). After 30 secondsimmersion the fabric was removed, squeezed through rollers to a totalweight of 200 parts and dried in hot air. In each case the fabric wasdyed to a level, well penetrated blue shade.

What we claim is:

1. In a process for the treatment of a textile material by scouring thetextile material with an organic solvent, removing the solvent from thetextile material in an aqueous flash-off stage and applying a memberselected from the group consisting of a dyestuff and finishing agent tothe textile material the improvement comprising applying the said memberin the flash-off stage.

2. Process as claimed in claim 1 wherein the said member is applied tothe textile material in a hot water flash-off bath.

3. Process as claimed in claim 1 wherein the textile material issubjected to an aqueous desizing step before it is scoured with theorganic solvent.

4. Process as claimed in claim 1 wherein the textile remains in asolvent-scouring bath for from 10 to seconds.

5. Process as claimed in claim 1 wherein the textile material remains inan aqueous bath containing the said member for up to 5 minutes.

6. Process as claimed in claim 5 wherein the textile material remains inthe aqueous bath for from 2 to 60 seconds.

References Cited UNITED STATES PATENTS 2,540,311 2/1951 Wolff 117-13852,729,576 1/1956 Trusler 252-D.C. 3,106,460 10/1963 TOpham et al 8-142X3,404,943 10/ 1968 Morris 8139 MAYER WEINBLATT, Primary Examiner US. Cl.X.R.

8-18, 138, 139; ll7--l37.5

Disclaimer 3,575,686.--J0hn William Oase, Norman Frederick Crowder, andWilfred Arthur Ste hen White, Runcorn, England. TREATMENT OF TEXTILEPatent dated Apr. 20, 1971. Disclaimer filed Dec. 15, 1969, by theassignee, Imperial Ohemz'eal Industries Limited. Hereby disclaims theportion of the term of the patent subsequent to Nov. 4, 1986.

[Ofiez'al Gazette September 1%, 1.972]

